The absorption and luminescence spectra of InSe nanoparticles synthesized by laser ablation in a liquid medium have been investigated experimentally. The radiation source was a pulsed Nd:YAG laser with built-in second and third harmonic generators, which was intended for generating radiation at wavelengths of 1064, 532, and 335 nm. The ablation was performed for ~ 10 min by the Nd:YAG laser at wavelength λ = 1064 nm, a pulse duration of 10 ns, an energy per pulse of 135 mJ, and a pulse repetition rate of 10 Hz in a quartz cuvette filled with distilled water. The bandgap width of InSe nanoparticles was calculated using the Tauc method. At high laser pumping intensities, a shift of the absorption band edge of InSe nanoparticles was observed in the short wavelength spectral region, and the peak of the luminescence spectrum of nanoparticles exceeded significantly the bandgap width of a bulk crystal. It is shown that the observed peculiarities in the absorption and luminescence spectra of InSe nanoparticles are associated with the quantum size effect.
Salmanov et al. (Thu,) studied this question.